Dialog button/message config schema types cause locale pollution (label/text instead of string)

Problem/Motivation

Config schema entries for dialog button labels and messages are defined with types label and text in autologout_alterable.schema.yml. These types are treated as locale-translatable source strings by Drupal's locale system, meaning that when a site stores a site-specific value (e.g. dialog_logout_button: 'Anything'), that string gets registered into the global locale translation table. This causes unintended side effects: if the original English value (e.g. "No") was ever translated or overridden, that translation leaks out and affects every other occurrence of that string across the entire site.

Steps to reproduce

1. Install the module with default config.
2. Override dialog_logout_button (default: "No") to a translated value, e.g. "Anything", via the settings form.
3. Observe that the word "No" is now replaced site-wide wherever Drupal's locale system resolves it.

Proposed resolution

Change the schema type for all dialog button/label/message fields from label/text to string in autologout_alterable.schema.yml. These values are site-specific UI strings stored directly in config and do not need to participate in the locale translation pipeline.